饲粮中植酸磷水平对生长肥育猪生产性能及植酸磷利用率的影响

24头长白猪(70日龄),随机等分为4组,喂以在玉米淀粉—豆饼为主的基础饲粮中添加不同量植酸钠组成植酸磷水平分别为0.065％、0.15％、0.25％、0.35％(占总磷水平分别为13％、30％、50％、70％)的4种饲粮,试验为期5周,研究饲粮中植酸磷水平对生长猪生产性能的影响。饲养试验结束后,从Ⅰ、Ⅲ、Ⅳ组各选3头公猪饲喂于木制代谢笼中,为期6天,进行全收粪法的代谢试验,研究生长肥育猪对植酸磷的利用率及与饲粮中植酸磷水平的关系。结果表明:1)随着饲粮中植酸磷水平升高,猪的日增重降低,植酸磷水平达0.35％时则极显著降低日增重和饲粮转化率(P<0.01)。2)生长猪对植酸磷的利用率为33％—36％,总磷的利用率40—60％,且与饲粮中植酸磷水平显著相关,相关系数分别为0.95(P<0.05),-0.87(P<0.05)。     

乳酸处理小麦和玉米对其植酸磷和抗性淀粉含量的影响

文章旨在研究乳酸浸泡处理小麦和玉米对植酸磷、抗性淀粉及营养成分的影响。试验选择玉米、小麦和小麦+玉米(1∶1混合),分别在0、10和25g/kg乳酸中浸泡0、6、12、24和48h。然后直接分析样品的营养成分或在21℃下保存4周直至分析。结果显示:乳酸对小麦、玉米、小麦-玉米养分的影响随乳酸浓度和浸泡时间的增加而更加明显,培养48h后以25g/kg乳酸处理的影响最大。在25g/kg乳酸中浸泡48h后,玉米、小麦和小麦-玉米总磷含量降低9%(P<0.05),植酸磷含量分别降低24%、30%和25%(P<0.05)。浸泡48h后,小麦和小麦-玉米中植酸酶活性显著降低(P<0.05)。虽然乳酸处理对总淀粉含量无显著影响(P>0.05),但浸泡在25g/kg乳酸中,小麦的抗性淀粉含量增加了51%(P<0.05),而玉米和小麦-玉米的抗性淀粉含量分别降低了52%和19%(P<0.05)。综上所述,乳酸处理小麦和玉米可以有效降低谷物中植酸磷的含量。在本试验条件下,小麦和玉米在25g/kg乳酸中浸泡48h是降低植酸磷含量的最适方案。     

日粮中不同类型大麦和不同蛋白质含量对生长猪氮、磷排泄量的影响

本试验研究了含有普通大麦（NB）或低植酸大麦（LPB）日粮（含有18％和15％蛋白质）对生长猪的氮和磷排泄量的影响。NB含有0．31％总磷和0．19％植酸磷;LPB含有0．32％总磷和0．01％植酸磷。结果表明：日粮中LPB代替NB,极显著地降低磷的排泄量：含有18％和15％蛋白质日粮,分别降低了38％和43％的磷排泄量（P〈0．001）。日粮CP含量从18％降到15％。极显著降低了N的排泄,含有NB和LBP日粮分别降低了29％和32％氮的排泄量（P〈O．001）。随着日粮蛋白质含量降低,极显著地降低了总氮的保留量（P〈0．001）。生长猪饲喂LPB型日粮的粪中的N：P比值比饲喂NB型日粮的高（P〈0．001）。总之,降低生长猪磷和氮的排泄量．可以通过LPB代替NB和也可以通过降低日粮中的CP含量。     

饲粮非植酸磷水平对褐壳蛋鸡植酸磷利用率的影响

150只蛋鸡随机分为5个处理组，5个处理组非植酸磷水平分别为0.2%,0.25%,0.3%,0.35%,0.4%，钙水平都为3.5%。结果表明：饲粮非植酸磷水平为0.2%时，蛋鸡对植酸磷的表观利用率为65．5％（P＜0．05）。饲粮非植酸磷水平对蛋鸡生产性能无明显影响（P＞0．05）。     

生长猪饲粮中植酸磷水平对体内矿物质代谢的影响

二十四头长白猪(70日龄),随机分为四组,饲喂在玉米淀粉—豆饼为主的基础饲粮中添加不同量植酸钠组成植酸磷水平分别为0.065%、0.15%、0.25%、0.35%(占总磷水平分别为13%、30%、50%、70%)的4种饲粮,试验期为五周,研究植酸磷对体内矿物质代谢的影响。结果表明:饲粮中植酸磷影响钙、锌、铜等元素的吸收利用,且这些元素的利用率与饲粮中植酸磷含量呈显著负相关,从而也影响了钙、磷、锌等元素在骨中沉积。饲粮中植酸磷水平达到0.35%时,钙、铜、锌、磷的吸收利用及其在骨中沉积量显著高于其它三个组,而这三组间则无显著差异,但表现出随饲粮中植酸磷水平升高,钙、铜、锌吸收利用及其在骨中沉积量呈下降趋势。     

饲喂不同蛋白质含量的低植酸盐的大麦、大豆对生长肥育猪的氮、磷排泄的影响

本试验探讨大麦基础日粮中不同粗蛋白质含量分别为18%、15%的基础上使用普通大麦或低植酸大麦,对4组生长猪的磷和氮排泄的影响。普通大麦组含0.31%的总磷和0.19%植酸磷;低植酸盐大麦组含0.32%的总磷和0.01%植酸磷。按照NRC(1998)标准,日粮补充足够的赖氨酸、蛋氨酸、苏氨酸和色氨酸,满足回肠表观消化率。普通大麦组中使用无机磷满足NRC(1998)有效磷的需要。低植酸盐大麦组中不需要使用无机磷,因为已经满足NRC(1998)有效磷(0.27%)的需要。8头阉公猪分成4组,按照4×4拉丁方设计,初始体重为20.9 kg。日粮中提供2.5倍维持需要的代谢能。饲喂2次/d,分别在08∶00和15∶00,等量饲喂。水与日粮按2.5:1混合。每个试验组共进行12d,7 d的适应期和5 d正式收粪尿期。结果显示,用低植酸盐大麦代替普通大麦减少总磷的排泄(P<0.001),18%和15%粗蛋白质组分别减少38%和43%。日粮粗蛋白质从18%减少到15%(P<0.001),相应的,对于普通大麦组,氮排泄减少29%,而低植酸盐大麦组减少32%。随着粗蛋白质的减少,氮固定也极显著减少(P<0.001)。低植酸盐大麦组粪尿中氮:磷比也极显著高于普通大麦组(P<0.001)。总之,对于生长肥育猪,通过用低植酸盐大麦代替日粮中的普通大麦,可以减少日粮中粗蛋白质含量,从而显著(P<0.001)减少磷和氮的排放。     

植酸酶对猪粪便中氮、磷及植酸磷排放量影响的研究

许多试验结果表明,日粮中添加植酸酶可改善畜禽的生产性能,提高磷利用率和矿物元素利用率。研究对生长育肥猪全期添加植酸酶进行试验,观察其对猪粪磷、植酸磷、粪氮排放量及生产性能的影响,以便为植酸酶的更广泛推广应用提供理论依据。     

饲用小麦总磷和植酸磷含量变异度的研究

选择我国6个小麦主产省区具有代表性的64个饲用小麦样品,测定其总磷和植酸磷含量,研究饲用小麦总磷和植酸磷含量变异度。结果发现:全国小麦主产区的小麦含磷量平均水平为0.37%,最小值为0.25%,最大值为0.48%,变异系数为4.89%～15.14%,四川省和河南省的变异系数最大;山东省饲用小麦总磷和植酸磷水平最高,平均水平分别为0.4%和0.3%;饲用小麦总磷和植酸磷之间存极显著正相关,植酸磷=0.766×总磷-0.019(r=0.841,P0.01)。     

猪磷营养与植酸磷研究进展

1磷的生物学价值及其评定 生物学价值（biological value）又称生物利用率，Ammerman等（1995）将营养素的生物学效价定义为，营养素被摄入后能在代谢中被利用的程度。生物学价值又分为绝对生物学价值和相对生物学价值，其中绝对生物学价值用于表示猪用消化率（weremko等，1997）。相对生物学价值（relative biological value，RBV）是以某种无机磷源的某一量化指标为参照标准，将待测磷源的同一量化指标与参照标准相比。     

Relationship between mineral availabilities and dietary phytate in animals

A large amount of phosphorus (P) in corn and soybean meal is in the form of phytate that is poorly available to monogastric animals. It leads to the presence of large amounts of P in manure, which contributes to the P pollution problem. The fermentation of soybean meal with Aspergillus usamii almost completely degraded phytate and improved P availability in chicks. Although dietary yeast phytase increased P absorption and availability in pigs, its efficacy was less than that of Aspergillus niger phytase. It was suggested that the lesser efficacy of yeast phytase resulted from its lower stability against pepsin. Phytate suppresses zinc availability in monogastric animals. Zinc availability was improved by the substitution of regular soybean meal with fermented soybean meal and by the supplementation with Aspergillus niger phytase in pigs. It has been considered that phytate is easily degraded in the rumen and the availability of phytate P is high in ruminants. However, 20% of phytate in oilseed meals was not degraded in the rumen of sheep. Additionally, heating and formaldehyde treatments with oilseed meals suppressed ruminal degradation of phytate and approximately half of phytate escaped from ruminal degradation in the treated oilseed meals.     

小麦及其副产物在猪营养中的价值

小麦是猪饲料中重要的能量原料,其淀粉含量高,与蛋白原料相比,其粗蛋白质含量相对较低,但其含大量必需氨基酸氨基酸。小麦副产物如麦麸、次粉和小麦酒糟及其可溶物在猪营养中越来越受到重视。特别是用于生物燃料生产后的小麦副产物,它们具有较高的粗蛋白质和粗脂肪水平。此外,小麦含有不同比例的非淀粉多糖,包括阿拉伯木聚糖、β-葡聚糖和果胶,这些成分可作为营养成分,但也可能影响营养物质的消化率。在以小麦和小麦副产物为基础的日粮中使用饲用酶可以降低非淀粉多糖对营养和能量消化率的负面影响,从而提高这些饲料成分的饲用价值。此外,一些加工方法,如粉碎、膨化、制粒、超微粉、发酵、青贮等均可提高猪饲粮中小麦的营养和能量消化率。本文对小麦及其副产物在猪营养中的营养价值进行综述,为其在猪营养中的应用价值提供参考。     

贮存时间对小麦和玉米青贮质量的影响

本研究旨在评价贮存时间对玉米和小麦青贮过程质量的影响。试验选择的原料为玉米和开花期及乳熟期小麦,将其放入1.5 L厌氧发酵罐重,分别发酵1周、2周、1个月、3个月、6个月和1年。贮存一年后,青贮玉米的干物质和中性洗涤纤维消化率显著下降(P <0.05)。干物质产量在贮存3个月后达到最大值(P <0.05)。开花期小麦pH随着贮存时间的延长而降低,乳酸含量在贮存3个月后最高(P <0.05),之后显著降低(P <0.05)。乳熟期小麦pH随贮存时间的升高而降低,乳酸含量在贮存3个月后最高(P <0.05),之后显著降低(P <0.05)。乙酸含量随着贮存时间升高而升高(P <0.05)。贮存时间显著影响青贮玉米干物质、干物质产量、乙酸、中性洗涤纤维消化率及CO_2产量(P <0.05),显著影响开花期小麦pH及CO_2产量(P <0.05),显著影响乳熟期小麦pH、干物质、灰分、乙酸含量、CO_2产量、中性洗涤纤维含量及干物质消化率(P <0.05)。玉米、开花期小麦和乳熟期小麦干物质的损失在3～6个月达到最大水平。乳酸在青贮1～3个月达到最大值,而乙酸则随贮存时间的升高而升高,这也是青贮料好氧稳定性随着时间的增加而升高的原因。     

Effects of high non‐phytate phosphorus starter diet on subsequent growth performance and carcass characteristics of broiler chickens

The trial was performed to investigate the effects of different concentrations of non‐phytate phosphorus (nPP) in the starter and grower (with phytase inclusion) periods on carcass characteristics, organ weight and weekly variations of growth performance in the grower period. Seven hundred and twenty‐day‐old male broiler chickens were randomly assigned to 12 treatments in a completely randomized design. Chickens received two dietary treatments (4.5 g/kg and 6 g/kg nPP) in the starter (0–21 days) and six experimental diets (4 g/kg, 3.1 g/kg, 2.3 g/kg and 2.3 g/kg + 1000 FTU/Kg of feed phytase, 1.5 g/kg, 1.5 g/kg nPP + 1000 FTU/Kg of feed phytase) in the grower period (22–42 days). Results showed that phytase inclusion in the second and third weeks of grower period could increase feed intake significantly. Also, decrease in the concentrations of nPP to 1.5 g/kg caused to decline body weight gain markedly. Moreover, there is a significant difference between 4.5 g/kg and 6 + 4 g/kg nPP (starter+grower) and 1.5 g/kg nPP. Phytase inclusion increased carcass yield and declined liver weight significantly. Dietary treatment of 4.5 + 1.5 g/kg nPP enhanced heart and liver weight markedly. It is concluded that starter diets with increased concentration of nPP (6 g/kg nPP) had no beneficial effects on growth performance in the starter and grower period in the total (0–42 days). Also, it is possible to decrease nPP concentration of grower diets to 1.5 and 2.3 g/kg with and without phytase inclusion respectively.     

Phytate in pig and poultry nutrition

Phosphorus (P) is primarily stored in the form of phytates in plant seeds, thus being poorly available for monogastric livestock, such as pigs and poultry. As phytate is a polyanionic molecule, it has the capacity to chelate positively charged cations, especially calcium, iron and zinc. Furthermore, it probably compromises the utilization of other dietary nutrients, including protein, starch and lipids. Reduced efficiency of utilization implies both higher levels of supplementation and increased discharge of the undigested nutrients to the environment. The enzyme phytase catalyses the stepwise hydrolysis of phytate. In respect to livestock nutrition, there are four possible sources of this enzyme available for the animals: endogenous mucosal phytase, gut microfloral phytase, plant phytase and exogenous microbial phytase. As the endogenous mucosal phytase in monogastric organisms appears incapable of hydrolysing sufficient amounts of phytate‐bound P, supplementation of exogenous microbial phytase in diets is a common method to increase mineral and nutrient absorption. Plant phytase activity varies greatly among species of plants, resulting in differing gastrointestinal phytate hydrolysis in monogastric animals. Besides the supplementation of microbial phytase, processing techniques are alternative approaches to reduce phytate contents. Thus, techniques such as germination, soaking and fermentation enable activation of naturally occurring plant phytase among others. However, further research is needed to tap the potential of these technologies. The main focus herein is to review the available literature on the role of phytate in pig and poultry nutrition, its degradation throughout the gut and opportunities to enhance the utilization of P as well as other minerals and nutrients which might be complexed by phytates.     

Effects of formulating growing pig diet with increasing levels of wheat‐corn distillers dried grains with solubles on digestible nutrient basis on growth performance and nutrient digestibility

Formulating swine diets containing fibrous coproducts based on net energy (NE) and standardized ileal digestible amino acid (SID AA) values is recommended for optimizing pig performance. However, the effects of applying this approach to diets with increasing dietary levels of wheat‐corn‐derived distillers dried grains with soluble (wcDDGS) on pig performance have not been evaluated. Thus, 48 pigs with an average body weight [BW] of 25.5 kg were used to determine the effects of increasing wcDDGS (1:1 wheat to corn ratio) content in grower diets on performance and apparent total tract digestibility (ATTD) of energy and nutrients. Pigs were housed in pens of either 2 barrows or gilts balanced for BW and fed 4 diets within sex for 42 days. Diets were a nutrient adequate corn–barley–soybean meal‐based diet with 0%, 10%, 20% and 30% wcDDGS, and were similar in calculated NE and SID AA values. Acid insoluble ash was used as the indigestible marker. Final BW and overall average daily gain (ADG) linearly decreased (p < 0.05) and feed efficiency tended to decrease (p = 0.07) with increased dietary wcDDGS. Overall average daily feed intake was not affected (p > 0.10) by dietary treatment. The ATTD of dry matter and energy linearly decreased (p < 0.01), whereas the ATTD of neutral detergent fibre linearly increased (p < 0.01) with increasing dietary level of wcDDGS. Increasing dietary wcDDGS content did not affect (p > 0.10) ATTD of Ca and P. In conclusion, increasing dietary wcDDGS content reduced growth performance and ATTD of energy in growing pigs. Thus, the risks of high dietary wcDGGS content may not be completely alleviated by formulating growing pig diets on the basis of NE and SID AA systems.     

Intrinsic phytase in hybrid rye increases the digestibility of phosphorus in corn and soybean meal in diets fed to growing pigs

An experiment was conducted to test the hypothesis that inclusion of hybrid rye in diets containing corn and soybean meal (SBM) without or with microbial phytase improves the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P because of the intrinsic phytase activity in hybrid rye. Forty-eight growing barrows (initial body weight: 39.5 ± 7.7 kg) were allotted to six diets. A basal diet containing corn and SBM; a rye-based diet; and a diet containing corn, SBM, and rye were formulated. Each diet was formulated without and with microbial phytase (500 units/kg of diet) for a total of six diets. Fecal samples were collected for 4 d following a 5-d adaptation period according to the marker-to-marker procedure. Results indicated that no interactions between diets and concentration of phytase were observed for any of the response criteria measured. The ATTD and STTD of P and the ATTD of Ca differed (P < 0.05) among diets, but regardless of diet, the concentration of P in feces was reduced (P < 0.05) by adding microbial phytase to the diets. As a consequence, microbial phytase increased (P < 0.05) ATTD and STTD of P, and the ATTD of Ca was also increased (P < 0.05) by the use of microbial phytase. Measured values for the ATTD and STTD of P in the diets containing corn, SBM, and hybrid rye without or with phytase were greater (P < 0.05) than values that were predicted based on the ATTD and STTD of P for the corn–SBM and the hybrid rye diet. The observation that STTD predicted from the individual ingredients underestimated the STTD of P in the mixed diet indicates that the intrinsic phytase in hybrid rye resulted in increased digestibility of the P in the corn and SBM included in the corn–SBM–hybrid rye diet. In conclusion, microbial phytase increased the ATTD and STTD of P and the ATTD of Ca regardless of feed ingredients used in diets fed to pigs. In addition, the intrinsic phytase from hybrid rye increased the ATTD and STTD of P in corn and SBM.     

小麦替代玉米对颗粒饲料性能的影响

本试验研究了用小麦替代玉米对颗粒饲料性能的影响。根据0～3周龄的樱桃谷肉鸭营养需要配制3种类型的试验日粮,即Ⅰ型(谷物饲料组成:玉米100%)、Ⅱ型(谷物饲料组成:玉米52.6% 小麦47.4%)、Ⅲ型(谷物饲料组成:玉米10.9% 小麦89.1%)。测定3种类型的颗粒饲料的密度、容重、硬度、粉化率。结果表明,小麦和玉米比例不同的日粮颗粒密度差异不显著(P>0.05),容重、硬度、粉化率差异极显著(P<0.01)。随着小麦添加比例的增加,颗粒饲料的容重、硬度增加,粉化率降低。